Finalize backend for fetching more NTPSnippets.

components/ntp_snippets/remote/ntp_snippets_service_unittest.cc

Index: components/ntp_snippets/remote/ntp_snippets_service_unittest.cc
diff --git a/components/ntp_snippets/remote/ntp_snippets_service_unittest.cc b/components/ntp_snippets/remote/ntp_snippets_service_unittest.cc
index c69d7ebaaf2ce3b19a9ea7310bda0314f7bdd70b..a31e0c6b8ca754c7b0727fa8170a69e4e2396e66 100644
--- a/components/ntp_snippets/remote/ntp_snippets_service_unittest.cc
+++ b/components/ntp_snippets/remote/ntp_snippets_service_unittest.cc
@@ -503,12 +503,12 @@ class NTPSnippetsServiceTest : public ::testing::Test {
     base::RunLoop().RunUntilIdle();
   }
 
-  void LoadMoreFromJSONString(
-      NTPSnippetsService* service,
-      const std::string& json,
-      NTPSnippetsService::FetchedMoreCallback callback) {
+  void LoadMoreFromJSONString(NTPSnippetsService* service,
+                              const std::string& json,
+                              std::set<std::string> known,

[dgn, 2016/11/02 11:10:11]

|known_ids| maybe? name is too unspecific as it is now.

[fhorschig, 2016/11/03 01:53:14]

Done.

+                              NTPSnippetsService::FetchingCallback callback) {
     SetUpFetchResponse(json);
-    service->FetchMore(articles_category(), callback);
+    service->Fetch(articles_category(), known, callback);
     base::RunLoop().RunUntilIdle();
   }
 
@@ -852,6 +852,7 @@ TEST_F(NTPSnippetsServiceTest, LoadsAdditionalSnippets) {
   std::string second("http://second");
   LoadMoreFromJSONString(service.get(),
                          GetTestJson({GetSnippetWithUrl(second)}),
+                         std::set<std::string>(),
                          base::Bind([](std::vector<ContentSuggestion>) {}));
   // The snippets loaded last are added to the previously loaded.
   EXPECT_THAT(service->GetSnippetsForTesting(articles_category()),
@@ -875,15 +876,24 @@ TEST_F(NTPSnippetsServiceTest, InvokesOnlyCallbackOnFetchingMore) {
   MockFunction<void(const std::vector<ContentSuggestion>&)> loaded;
   EXPECT_CALL(loaded, Call(SizeIs(1)));
 
-  LoadMoreFromJSONString(service.get(),
-                         GetTestJson({GetSnippetWithUrl("http://some")}),
-                         base::Bind(&SuggestionsLoaded, &loaded));
+  LoadMoreFromJSONString(
+      service.get(), GetTestJson({GetSnippetWithUrl("http://some")}),
+      std::set<std::string>(), base::Bind(&SuggestionsLoaded, &loaded));
 
   // The observer shouldn't have been triggered.
   EXPECT_THAT(observer().SuggestionsForCategory(articles_category()),
               IsEmpty());
 }
 
+TEST_F(NTPSnippetsServiceTest, ReturnFetchRequestEmptyBeforeInit) {
+  auto service = MakeSnippetsServiceWithoutInitialization();
+  MockFunction<void(const std::vector<ContentSuggestion>&)> loaded;
+  EXPECT_CALL(loaded, Call(SizeIs(0)));
+  service->Fetch(articles_category(), std::set<std::string>(),
+                 base::Bind(&SuggestionsLoaded, &loaded));
+  base::RunLoop().RunUntilIdle();
+}
+
 TEST_F(NTPSnippetsServiceTest, LoadInvalidJson) {
   auto service = MakeSnippetsService();